[ILUG] New system - final preparations before deployment.

[Paul Jakma]

On Tue, 7 Sep 2004, Conor Wynne wrote:

> Yes, I did actually think of that. But since the system has 1GB 
> RAM, and -so far- swap does not even come into the equation (I will 
> not -yet- be running any databases on it)

Just having swap means stuff will be swapped out. And even if nothing 
is swapped out, I wouldnt want to bet that the box will survive a 
failure of swap.

Also, if you want redundancy, there's no point putting swap on RAID0. 
Swap can already do it's 'striping' across swap partitions of same 
priority, why unneccessarily go through the MD layer?

> I had a case with an "unnamed company" with 46 days of uptime with 
> no probs. Oracle 10G db and other development apps etc. On day 47, 
> everything slowed to a crawl and they were getting zombies (oracle 
> processes unsurprisingly). The problem was indeed due to lack of 
> swap space on a 512MB system. As soon as I added some swap the 
> system immediately started using it and the system became usable 
> again.

Weird, sounds like a bug.

> OK, what I can do is add a spare swap "file" instead of a real type 82
> jobby. I do not think I will go near the swappiness proc settings on this
> box.

swap files are slower.

> Hmm, must look into that. But first I will monitor it over a month 
> or so and see if it actually uses swap space.

If you have programmes 'running' that are mostly inactive, you will 
use swap - which is a good thing, it means more RAM is free.

> Aha, but thats where the wonderfull installer cd from fedora2 comes 
> in.

Yes, anaconda in FC2 does rock alright. :)

> All I have to do is boot from either a rescue cd, or type "linux 
> rescue" on CD1 on fedora core2, and then chroot blah blah and I'm 
> in. Sweet :)

ah, fair enough. I never have the CDs around, nor even a CDROM in 
most machines, so that option isnt available to me. A grub floppy and 
access to the rootfs and maybe init=bash is my means of rescue.

> Lucan, Capitale mondiale, not too far from Niall actually.
> The wesht is the besht :)

Excellent... do let us know how you get on with the server in the 
back garden... oh, and when you register that domain be sure to fill 
in whois data correctly...

regards,
-- 
Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
Fortune:
The First Rule of Program Optimization:
 	Don't do it.

The Second Rule of Program Optimization (for experts only!):
 	Don't do it yet.
 		-- Michael Jackson